plzz answer for this question
Answers
Step-by-step explanation:
Given that
X=-2 is a root so
3(-2)^2 - 14+p=0
12-14+p=0
P=2
So the equation is
3x^2+7x+2=0
Now we need to find k
We know that sum of roots fornula is - b/a
For first equation it is - 7/3
And second equation it is - 4k
Also given that roots are equal for two equations
So 7/3 =4k
K=7/28
Plz mark as brainliest
Given :-----
- x = (-2) is a factor of 3x²+7x+p = 0
To Find :----
- Value of k for which roots are Equal ..
Concept used :--------
→ if x = a is the roots of Equation p(x) , than , p(a) will be Equal to zero ...
→ If A•x^2 + B•x + C = 0 ,is any quadratic equation,
then its discriminant is given by;
D = B^2 - 4•A•C
• If D = 0 , then the given quadratic equation has real and equal roots.
• If D > 0 , then the given quadratic equation has real and distinct roots.
• If D < 0 , then the given quadratic equation has unreal (imaginary) roots.
_____________________________________
Solution :----
since x=-2 is factor of 3x²+7x+p=0 , hence , f(-2) = 0
→ f(-2) = 3(-2)² + 7*(-2) + p = 0
→ f(-2) = 3*4 -14 + p = 0
→ (-2) + p = 0
→ p = 2 ...
__________________________
Now, root of Equation x²+k(4x+k-1) + p = 0 are Equal .
Hence,
D = b² - 4ac = 0
Here,
x² + 4kx + (k² - k + p) = 0
→ a = 1
→ b = 4k
→ c = (k² - k + p) ,putting p = 2 now , (k²-k+2)
Putting values now we get,
⇒ 16k² – 4*1*(k² – k + 2) = 0
⇒ 4(4k² - k² +k -2) = 0
⇒ 3k² + k – 2 = 0
⇒ 3k² +3k - 2k -2 = 0
⇒ 3k(k+1)-2(k+1) = 0
⇒ (3k – 2)(k + 1) = 0
Putting both Equal to zero now, we get,
➠ 3k - 2 = 0 ,
➠ k = 2/3 ....
and,
➠ k + 1 = 0
➠ k = (-1)
____________________________________
Hence, value of k will be (2/3) and (-1) ..
#BAL
#answerwithquality